82 lines
4.5 KiB
Plaintext
82 lines
4.5 KiB
Plaintext
page.title=Building and Running
|
|
@jd:body
|
|
|
|
<div id="qv-wrapper">
|
|
<div id="qv">
|
|
<h2>In this document</h2>
|
|
<ol>
|
|
<li><a href="#detailed-build">A Detailed Look at the Build Process</a></li>
|
|
</ol>
|
|
</div>
|
|
</div>
|
|
|
|
<p>During the build process, your Android projects are compiled and packaged into an .apk file,
|
|
the container for your application binary. It contains all of the information necessary to run
|
|
your application on a device or emulator, such as compiled <code>.dex</code> files (<code>.class</code> files
|
|
converted to Dalvik byte code), a binary version of the <code>AndroidManifest.xml</code> file, compiled
|
|
resources (<code>resources.arsc</code>) and uncompiled resource files for your application.</p>
|
|
|
|
<p>If you are developing in Eclipse, the ADT plugin incrementally builds your project as you
|
|
make changes to the source code. Eclipse outputs an <code>.apk</code> file automatically to the bin folder of
|
|
the project, so you do not have to do anything extra to generate the <code>.apk</code>.</p>
|
|
|
|
<p>If you are developing in a non-Eclipse environment, you can build your project with the
|
|
generated <code>build.xml</code> Ant file that is in the project directory. The Ant file calls targets that
|
|
automatically call the build tools for you.</p>
|
|
|
|
<p>To run an application on an emulator or device, the application must be signed using debug or
|
|
release mode. You typically want to sign your application in debug mode when you develop and test
|
|
your application, because the build tools use a debug key with a known password so you do not have
|
|
to enter it every time you build. When you are ready to release the application to Android
|
|
Market, you must sign the application in release mode, using your own private key.</p>
|
|
|
|
<p>Fortunately, Eclipse or your Ant build script signs the application for you in debug mode
|
|
when you build your application. You can also easily setup Eclipse or your Ant build to sign your
|
|
application in release mode as well. For more information on signing applications, see <a href=
|
|
"{@docRoot}guide/publishing/app-signing.html">Signing Your Applications</a>.</p>
|
|
|
|
<p>The following diagram depicts the components involved in building and running an application:</p>
|
|
|
|
<img src="{@docRoot}images/build-simplified.png" />
|
|
|
|
<h2 id="detailed-build">A Detailed Look at the Build Process</h2>
|
|
|
|
<p>The build process involves many tools and processes that generate intermediate files on the
|
|
way to producing an <code>.apk</code>. If you are developing in Eclipse, the complete build process is
|
|
automatically done periodically as you develop and save your code changes. If you are using other
|
|
IDEs, this build process is done every time you run the generated Ant build script for your
|
|
project. It is useful, however, to understand what is happening under the hood since much of the
|
|
tools and processes are masked from you. The following diagram depicts the different tools and
|
|
processes that are involved in a build:</p>
|
|
|
|
<img src="{@docRoot}images/build.png" />
|
|
|
|
<p>The general process for a typical build is outlined below:</p>
|
|
|
|
<ul>
|
|
|
|
<li>The Android Asset Packaging Tool (aapt) takes your application resource files, such as the
|
|
<code>AndroidManifest.xml</code> file and the XML files for your Activities, and compiles them. An <code>R.java</code> is
|
|
also produced so you can reference your resources from your Java code.</li>
|
|
|
|
<li>The aidl tool converts any <code>.aidl</code> interfaces that you have into Java interfaces.</li>
|
|
|
|
<li>All of your Java code, including the <code>R.java</code> and <code>.aidl</code> files, are compiled by the Java
|
|
compiler and .class files are output.</li>
|
|
|
|
<li>The dex tool converts the .class files to Dalvik byte code. Any 3rd party libraries and
|
|
.class files that you have included in your project are also converted into <code>.dex</code> files so that
|
|
they can be packaged into the final <code>.apk</code> file.</li>
|
|
|
|
<li>All non-compiled resources (such as images), compiled resources, and the .dex files are
|
|
sent to the apkbuilder tool to be packaged into an <code>.apk</code> file.</li>
|
|
|
|
<li>Once the <code>.apk</code> is built, it must be signed with either a debug or release key before it can
|
|
be installed to a device.</li>
|
|
|
|
<li>Finally, if the application is being signed in release mode, you must align the <code>.apk</code> with
|
|
the zipalign tool. Aligning the final <code>.apk</code> decreases memory usage when the application is
|
|
running on a device.</li>
|
|
</ul>
|
|
|